*HOT* | Corsair DOMINATOR GT | 6GB (3x2GB) | DDR3-2000 7-8-7-20 @ 1.65V | *HOT*

[cstkl1]

check the BR review on xcpus.com, they compared it to the classified and saw the same weird perf drops, it only seems to affect some memory dividers... it could be that you have to manually adjust the mch straps for the diferent memory dividers... i dont know why clock for clock the classified is slower, but i wouldnt be surprised if its caused by some relaxed timings they use to get higher bclock/qpi speeds? i dont know if you can actually adjust this and get back to tight timings and good clock per clock performance for people who really dont need high bclocks...

yeah i thought so too, but i dont think its turbo since it affects diferent mem speeds... some speeds are fine, some are notably slow

thats odd about dfi btw, are you saying they decide when to chose what strap and dont allow users to adjust it manually in bios? thats kinda weird for dfi...

but with lower memory multiplier and same uncore multiplier you can get higher? try more vtt and... i dont know how they are called on the evga board, but increase the x58 voltages, theres a 1.1 and a 1.5v voltage, increase both and see if it helps... can you get higher with cas8? i was quite surprised when raja showed how much memory can hold you back bclock wise... he switched from some good samsung to some good elpida sticks and it gave him 10mhz higher bclocks or even more iirc... and he couldnt get those even with relaxed timings before...

its weird, and i dont really get why... but several people had the same experience, they couldnt get high bclocks even with high vdimm, vtt and loose timings, then switched to another set of mem and could get noticably higher bclocks then...

whats the highest bclock you can boot at SAE?
your on phase change right?

dfi mem skews are which are evga mem strap equivalent are set by bootup clocks.
so far tested that up to 204 bclk dram 2040 is perfect.
bclk 205 dram multi 10 above theres a issue. it will pass linx 100 runs
but will fail prime one thread error.
jimmy send me one relax mem skew bios 06/19. so far no diff. the rtls were relaxed as it is related to mem skew strength also.
so the problem could be this.
at bclk 205 onwards .. bios set 205, bios bootup at 204 and software read is 205. so i asked him whether is it because of this -1 that is causing the issue wince bootup clock would be 190 for 205 and would be exact.
tested with bios bclk 204, bootup 190 , bios bootup read 204, software read 204 and then used setfsb to up the bclk to 204.8-205.2. still the one thread error on prime 95 large fft custom 5.4gb

so no idea whats wrong atm.

also for the evga classified. the performance drop could be related to the vtt pwm frequency. hear me out on this. On the dfi lower pwm frequency gives better results on sp1m. infact its the key for stability and lowering vtt and vcore. so far i find for my board and proc setting -15 on vtt and nominal on dram is the best. heck vista boot up gain is by one bar by just doing this.

dfi mem sub timing are interesting say for C7
mem multi 6,8,10 , for TRFC,TWR,TWTR,TRRD,TRC,TRTP,TFAW on the bios would be
88,6,4,4,15,3,15
88,10,5,5,25,5,25
88,12,6,6,30,6,30

what i found interesting on the evga and dfi is say for bclk 205 i choose dram multi 8 but i set timings according to dram multi 10. it is more relax right.. but this will get prime95 custom 5.4gb thread errors. evga has no problem with this.

found that interesting.
and the evga the twr according the cpu tweaker i can change it but the dfi i cant atm on software read

[SAE]

but with lower memory multiplier and same uncore multiplier you can get higher? try more vtt and... i dont know how they are called on the evga board, but increase the x58 voltages, theres a 1.1 and a 1.5v voltage, increase both and see if it helps... can you get higher with cas8? i was quite surprised when raja showed how much memory can hold you back bclock wise... he switched from some good samsung to some good elpida sticks and it gave him 10mhz higher bclocks or even more iirc... and he couldnt get those even with relaxed timings before...

its weird, and i dont really get why... but several people had the same experience, they couldnt get high bclocks even with high vdimm, vtt and loose timings, then switched to another set of mem and could get noticably higher bclocks then...

whats the highest bclock you can boot at SAE?
your on phase change right?

Hi Sascha,

I already increased those voltages to several different values to check out what's holding me back. So far I had no real success... Vtt I tried 1.475V BIOS as max. I can do 4GHz UC at 1.35V BIOS easily (1.324V DMM). But increasing bclk to pump up the mem clocks and holding the tight timings it needs about 1.425V for stable 4.1-4.18GHz UC... At 4.2GHz UC it needs about 1.45Vtt set. I got nice priming results at 19x211 using 10x Mem 7-8-7-20 1T and 1.66Vdimm BIOS. But as soon as I up the CPU Multi to 20x it is getting unstable. So my conclusion is that IMC is hindering me. Voltages upped it's still a mystery what could get me stability finally. It's like cstkl1 said...

Highest bootable bclk is at about 221-222MHz for me and my GTX. Dunno whay others can boot at 226MHz Bclk (DFI maybe because of their seperate bootup setting), but I read something about the vid card influencing bootup bclk. I would love to try getting 20x226 stable at 902 Mem 6-6-5-18 Eleet is of no great help in this case.

[Raja@ASUS]

also for the evga classified. the performance drop could be related to the vtt pwm frequency. hear me out on this. On the dfi lower pwm frequency gives better results on sp1m. infact its the key for stability and lowering vtt and vcore. so far i find for my board and proc setting -15 on vtt and nominal on dram is the best. heck vista boot up gain is by one bar by just doing this.

PWM switching frequency should have zero impact on performance assuming a BIOS is not dorked in other ways.

[cstkl1]

PWM switching frequency should have zero impact on performance assuming a BIOS is not dorked in other ways.

yup just said a theory

yet the faster bootup in windows with reduce vtt pwm frequency is because of??

[Raja@ASUS]

yup just said a theory

yet the faster bootup in windows with reduce vtt pwm frequency is because of??

Because the BIOS is dorked, the 'theory' is misleading. PWM switching frequency at the power rails has nothing to do with system latency. The switching frequency is merely on/off switching over time, the output voltage is determined by the duty cycle. All this points to is that the DFI BIOS still has issues, nothing more.

[Mellowyellow]

Great write up and testing, I was like "holy crap" when I saw the Sandra bench

[AceBaran]

Is my cpu crap or is it the motherboard ? I cant even boot with anything lower then qpi/dramm 1.6 and vdimm 1.65.. i got these ramms the first week they where released and been running them at c8-8-8-20 2n since i couldnt pass linX with 7-8-7-20 on these volts.
I was kinda scared to raise the vdimm. I am also puzzled how you guys can get those timings with qpi/dramm 1.40 and vdimm 1.58 or less.
But today im like to hell with it... i bought these ramms with the 7-8-7-20 specs so im gonna runn it. Got them on 7-7-7-20 on 1.6 qpi and 1.68 vdimm and passed linx.

My question is : what is more likely to damage with higher volt on the ramm and qpi, the ramm or cpu? and how high can i go with the volt for a "safe" result?

Edit: no go on those timings, didnt pas linx on 4096 mb errored on 13 sec ..
got timings on 9-9-9-20 and running linx also errored on 2.46 min

I dont understand this ....
Anyone wanna buy my rig :p

>_<

[AceBaran]

fixed

[lutanica]

Hello mates

I can't make these memories run stable at 2000Mhz 7-8-7-20 (1T & 2T) with:

BLCK: 200
CPU Ratio: 19

I have been overclocking for a long time but it seems that something is wrong. I have adjusted CPU voltage from 1.38 - 1.42 and QPI voltage from 1.6 - 1.65 (with CPU PLL: 1.96) with no luck at all.
I have also adjusted DIMM voltage from 1.66 - 1.68. But the system crashes after some tests (under Prime95 8kb round). Here are the settings:









Please, could someone tell me what the hell is wrong?
I have got the Thermaltake Extreme True Copper with 2 big fans. So the temp is not the issue.


My system spec:

Asus P6T6 WS Revolution (last BIOS)
Intel i7 940
3x 1GB Dominator GT 7-8-7-20 2000MHZ
Corsair 1000W


Best Regards

[eva2000]

might not need as much QPI/DRAM volts as you think start with 1.4-1.45v QPI/DRAM (that scale up from there) with 1.66v vdimm and set CPU PLL to 1.8v default. Also 1.42v for 3.8ghz is alot of voltage even for C0 stepping cpu. Probably better to buy a new/better clocking cpu

[lutanica]

might not need as much QPI/DRAM volts as you think start with 1.4-1.45v QPI/DRAM (that scale up from there) with 1.66v vdimm and set CPU PLL to 1.8v default. Also 1.42v for 3.8ghz is alot of voltage even for C0 stepping cpu. Probably better to buy a new/better clocking cpu

Thanks mate for the response. If the QPI/DRAM goes under 1.58 (almost 1.6), windows won't load up (the PC resets before windows loads up). It's the base QPI/DRAM voltage that Corsair recommends for these Dominator GT (if I want to run the memories at the default speed 2000Mhz 7-8-7-20 1T). Could high Vcore voltage cause crash even though the temps are OK? I have tested Vcore voltages from 1.38 to 1.42 as I said before. It does not help. I still get BSOD when Prime95 begins with the 8K test.

[SAE]

8K is more like cpu errors... L1 and L2 iirc.

[lutanica]

8K is more like cpu errors... L1 and L2 iirc.

Thanks mate for the response. But the thing is that I tested BLCK 200 with DRAM frequency 1600mhz (one notch below Dominator GTs stock speed which is 2000Mhz) then the Prime95 test was perfect. No blue screen or anything.

I also ran Memtest for about 4 hours without any error (the system was overrclocked: BLCK: 200 CPU Multiplier: 19 DRAM Frequency: 2000Mhz 7-8-7-20 1T as it shows in the pictures above). How is that possible?

[cstkl1]

Thanks mate for the response. But the thing is that I tested BLCK 200 with DRAM frequency 1600mhz (one notch below Dominator GTs stock speed which is 2000Mhz) then the Prime95 test was perfect. No blue screen or anything.

I also ran Memtest for about 4 hours without any error (the system was overrclocked: BLCK: 200 CPU Multiplier: 19 DRAM Frequency: 2000Mhz 7-8-7-20 1T as it shows in the pictures above). How is that possible?

what he meant is not necessarily means vcore or cpu speed
could be uncore/vtt/qpi .

8k is normally cpu voltage error.. so its either vcore,vtt,qpi
overvolting is a bad thing for i7.. it infact can cause bsods and errors

also hmm found interesting that dram multi 10 ure twr is at 15.. instead of 12

also ure rtl is wrong for the third channel for sure it cant be the same as channel B

[SAE]

54-57-59 or 54-56-58 would be optimal for RTL in most cases as cstkl1 mentioned the RTLs.^^

To find the right balance of voltages is the key to success... I was already priming 2114 7-8-7-20 1T successfully at 1.67V. That's been Prime 64Bit Custom using 5.5GB of RAM under 7 x64.

[cstkl1]

would really like to see that
overall i find 7-7-6-18 to be slower than 7-7-7-20
and my kit no difference in vdimm for 7-7-7-20 vs 7-8-7-20

the new dfi bios rtl are a bit higher aka 55,57,59
no choice to use this bios since its the w7 fix for turbo.

but yup those are the best rtl's for elpida hypers c7.

[SAE]

I was already posting it before.

[leonarderman]

Here's my Corsair Dominator GT 2000MHz Cas 7 overclocking after one stick was died CPU on Water, Ram on air

[sofos1990]

wow! Man your sticks should be very very good
Wish I had one kit of these

[cstkl1]

sae
nice 1.7v++ for 2k C7.. 24/7

[Ronbo56]

sae
nice 1.7v++ for 2k C7.. 24/7

Received mine today Batch # 09360855 so far stable at 7-7-7-20 1T at 1.67V 1047 MHZ.

[The_Overclocker]

This is what [Young]pro thinks of these sticks btw. Am posting it as he probably isn't sure how...

Here

[SAE]

Received mine today Batch # 09360855 so far stable at 7-7-7-20 1T at 1.67V 1047 MHZ.

Great kit, mate. IF it's really stable.

[Ronbo56]

Great kit, mate. IF it's really stable.

its stable, but I'm having a problem posting my screen shots.

[cstkl1]

its stable, but I'm having a problem posting my screen shots.

lol.. screenshot dude .. if not i didnt happen.
btw if its stable whats so hard for screenshot
press print screen
open paint in accessories
paste
crop it smaller
and save.

then upload to
www.photobucket.com
choose forum posting hyperlinks.
copy it
and paste it here.

or just load to rapidshare and post the link.


again its not about the sticks..
its actually mobo settings and proc.

8 hours of prime95 5.4gb min like what SAE has been posting.